U.S. patent number 4,763,799 [Application Number 07/097,835] was granted by the patent office on 1988-08-16 for modular utility cart including improved structures for securing intermediate and top shelves to corner posts.
This patent grant is currently assigned to InterMetro Industries Corporation. Invention is credited to Robert J. Cohn, Jeffrey W. Rosania, W. Stanley Rosania, Michael J. Sudimak.
United States Patent |
4,763,799 |
Cohn , et al. |
August 16, 1988 |
**Please see images for:
( Certificate of Correction ) ** |
Modular utility cart including improved structures for securing
intermediate and top shelves to corner posts
Abstract
A modular utility cart includes four corner posts, at least one
intermediate shelf and a top shelf. The cart incorporates improved
structures for securing the intermediate and top shelves to the
posts. Specifically, each intermediate shelf is formed with four
open collars each for embracing one post. Each collar has a
cross-section substantially congruent to the cross-section of the
associated post, and has an upper right tubular portion embracing
the post, a lower tubular portion having a downwardly outwardly
inclined inner surface, and a transition portion between the upper
and lower portions. The top shelf, which is mountable in the region
of the tops of the posts, is formed with four blind tubular
collars, each having a downwardly outwardly inclined inner surface
and an inwardly projecting retaining flange at the bottom edge of
the surface. Four sleeves are provided for each intermediate shelf
and for the top shelf and each includes upper and lower edges, a
right tubular inner surface for closely embracing a post, and a
downwardly outwardly inclined outward surface matable with the
inner surface of either the open collar or the blind collar.
Inventors: |
Cohn; Robert J. (Dallas,
PA), Rosania; W. Stanley (Stockton, NJ), Rosania; Jeffrey
W. (Bloomsbury, NJ), Sudimak; Michael J. (Shavertown,
PA) |
Assignee: |
InterMetro Industries
Corporation (Wilkes-Barre, PA)
|
Family
ID: |
22265370 |
Appl.
No.: |
07/097,835 |
Filed: |
September 17, 1987 |
Current U.S.
Class: |
211/187;
108/147.13; 211/208; D34/20 |
Current CPC
Class: |
A47B
31/00 (20130101); A47B 57/265 (20130101); F16B
7/02 (20130101); F16B 7/0413 (20130101); F16B
7/105 (20130101); A47B 2031/004 (20130101) |
Current International
Class: |
A47B
31/00 (20060101); A47B 57/00 (20060101); A47B
57/26 (20060101); F16B 7/04 (20060101); F16B
7/10 (20060101); F16B 7/00 (20060101); F16B
7/02 (20060101); A47F 005/00 () |
Field of
Search: |
;211/187,208,186,181
;248/243 ;108/106,107,144 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gibson, Jr.; Robert W.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
What is claimed is:
1. A device for securing an element to a column, comprising:
means cooperating with said element and defining a collar for
embracing said column, said collar having a cross-section
substantially congruent to the cross-section of said column, an
upper right tubular portion closely embracing said column, a lower
tubular portion having downwardly outwardly inclined inner side
surfaces, and a transition portion between said upper portion and
said lower portion; and
a sleeve having an upper edge, a right tubular inner surface
closely embracing said column and a downwardly outwardly inclined
outer surface formed to mate with said lower tubular portion of
said collar,
whereby downward movement of said collar about said sleeve on said
column causes said respective inclined surfaces of said lower
portion and said sleeve to mate and inwardly compress said sleeve
toward said column, such downward movement being limited by
abutment of said top edge of said sleeve with said transition
portion of said collar.
2. A device according to claim 1, wherein said column is a right
cylinder, said cross-section of said collar is circular and said
inner surface and said outer surface of said sleeve have circular
cross-sections.
3. A device according to claim 1, further comprising means for
locating said sleeve at discrete locations along the axis of said
column.
4. A device according to claim 1, wherein said transition portion
of said collar is downwardly outwardly inclined at an angle to the
axis of said collar substantially greater than that of downward
outward inclination of said lower portion.
5. A device according to claim 4, wherein said top edge of said
sleeve is downwardly outwardly inclined at an angle to the axis of
said sleeve substantially the same as that of downward outward
inclination of transition portion.
6. A device according to claim 1, where said collar is made of
plastic material.
7. A device for securing an element to a column, comprising:
a sleeve having upper and lower edges, a right tubular inner
surface for closely embracing said column, and a downwardly,
outwardly inclined outer surface; and
means cooperating with said element and defining a blind tubular
collar having a downwardly outwardly inclined inner surface formed
to mate with said outer surface of said sleeve, and an inwardly
projecting retaining flange formed to underlie said lower edge of
said sleeve when said outer surface of said sleeve and said inner
surface of said collar are in mating relation,
whereby downward movement of said collar about said sleeve on said
column causes said retaining flange initially to override said
outer surface of said sleeve to permit said outer surface of said
sleeve to mate with the inner surface of said collar, whereby
further such downward movement causes said collar to inwardly
compress said sleeve toward said column and causes said retaining
flange to underlie said lower edge of said sleeve, and whereby
subsequent upward movement of said collar is resisted by engagement
of said retaining flange on the lower edge of said sleeve.
8. A device according to claim 7, wherein said column is a right
cylinder, said sleeve has a right cylindrical inner surface and the
cross-section of said outer surface of said collar is circular.
9. A device according to claim 7, further comprising means for
locating said sleeve at a fixed axial position on said column when
said inner surface of said collar mates with the outer surface of
said sleeve.
10. A modular utility cart comprising:
a plurality of support posts;
at least one intermediate shelf mountable on said posts, said
intermediate shelf including means defining a plurality of open
collars each for embracing one said post, each said collar having a
cross-section substantially congruent to the cross-section of one
said post, an upper right tubular portion closely embracing said
post, a lower tubular portion having a downwardly outwardly
inclined inner surface, and a transition portion between said upper
portion and said lower portion;
a top shelf mountable in the region of the tops of said posts, said
top shelf including means defining a plurality of blind tubular
collars each having a downwardly outwardly inclined inner surface
and an inwardly projecting retaining flange in the region of the
bottom of said inner surface; and
a plurality of sleeves, one for each open collar of said
intermediate shelf and for each blind collar of said top shelf,
each said sleeve including upper and lower edges, a right tubular
inner surface closely embracing one said post and a downwardly
outwardly inclined outer surface matable with said lower portion of
said inner surface of said open collar and said inner surface of
said blind collar;
whereby downward movement of one said open collar about one said
sleeve on an associated post causes said respective inclined inner
surface of said open collar and said inclined outer surface of said
sleeve to mate and inwardly compress said sleeve toward said
associated post, said downward movement being limited by abutment
of said top edge of said one sleeve with said transition portion of
said one open collar; and
whereby downward movement of one said blind collar about another
said sleeve positioned in the region of the top of an associated
post causes said retaining flange initially to override said outer
surface of said other sleeve to permit said outer surface of said
other sleeve to mate with said inner surface of said one blind
collar whereby further such downward movement compresses said other
sleeve toward said post and causes said retaining flange to
underlie said lower edge of said sleeve, and whereby subsequent
upward movement of said blind collar is resisted by engagement of
said retaining flange on the lower edge of said other sleeve.
11. A modular utility cart according to claim 10, wherein each said
post is a right cylinder, said cross-section of each said open
collar is circular, and said inner surface and said outer surface
of said sleeve have circular cross-sections.
12. A modular utility cart according to claim 10, further
comprising means for locating each said sleeve at discrete
locations along the axis of an associated post.
13. A modular utility cart according to claim 10, wherein said
transition portion of each said open collar is downwardly outwardly
inclined at an angle to the axis of said collar substantially
greater than that of downward outward inclination of said lower
portion.
14. A modular utility cart according to claim 13, wherein said top
edge of each said sleeve is downwardly outwardly inclined at an
angle to the axis of said sleeve substantially the same as downward
outward inclination of said transition portion of each said open
collar.
15. A modular utility cart according to claim 10, wherein each said
post is a right cylinder, each said sleeve has a right cylindrical
inner surface and an surface having a circular cross-section.
16. A modular utility cart according to claim 10, further
comprising means for locating one said sleeve at a fixed position
in the region of the top of each said post when said inner surface
of one said blind collar mates with the outer surface of such
sleeve.
17. A modular utility cart according to claim 10, each further
comprising a metal boss embracing the outer outer surface of each
said blind collar, said retaining flange being provided on a bottom
edge of said boss.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to devices for transporting
portable articles and may be used with particular advantage in
hospitals, hotels, schools, and the like. More particularly, the
present invention relates to a modular, knock-down utility cart
that is easy to manufacture, to ship in knocked down condition from
the point of manufacture to the point of use, and that can be
easily assembled and later disassembled for compact storage. Still
further, this modular utility cart incorporates improved structures
for mounting intermediate shelves and a top shelf on corner
supporting posts.
2. Description of the Prior Art
Utility carts of the type described above are ordinarily provided
with four casters. They may include four corner posts, a handle at
one or both ends of the cart, and two or more shelves such as a top
and an intermediate shelf supported by the corner posts. Such carts
have been manufactured as unitary welded or otherwise assembled
structures or in knock-down modular form.
One problem with unitary utility carts employing, for example,
welded construction, is that they are expensive to store and ship
because of their size. Additionally, they may not be disassembled
for compact storage when not in use.
The advent of knock-down utility carts constitutes a substantial
improvement over carts having unitary construction. One such
knock-down utility cart is described and illustrated in U.S. Pat.
No. 4,595,107 (Welsch) assigned to the Assignee of the subject
invention. This device generally incorporates four-corner posts,
each of which is provided with a caster at its bottom and two or
more shelves are mounted on the corner posts using the InterMetro
Industries SUPER ERECTA modular shelving system. The device also
incorporates an improved modular handle arrangement. U.S. Pat. Nos.
3,424,111 (Maslow) and 3,757,705 (Maslow), also assigned to the
Assignee of the subject invention, describe the SUPER ERECTA
system, which generally incorporates four right cylindrical corner
posts each formed with a plurality of regularly spaced angular
grooves along the axis of the post. Each shelf is provided with a
frustoconical collar that receives a similar frustoconical sleeve
which in turn embraces the post. Downward movement of the shelf
causes the collar and sleeve to interengage thereby inwardly
compressing the sleeve against the post. The sleeve shown in U.S.
Pat. No. 3,757,705 includes an annular outwardly projecting flange
at its bottom edge which is said to limit downward movement of a
collar on the sleeve. However, this exposed flange has a tendency
to collect contaminants and, therefore, may become unsanitary.
Further, in shelving system and particularly utility cart
applications, it may be desirable to make shelves out of plastic
material such as structural foam. However, because of the inherent
nature of such material, they exhibit plastic deformation or tend
to "creep". If plastic is used in shelving in the SUPER ERECTA
system a frustoconical collar formed directly in the plastic shelf
has a tendency to expand radially outwardly as it engages the outer
frustoconical surface of a sleeve. Thus, the collar in the shelf
may eventually override the sleeve in such a way as to cause the
structural integrity of the system significantly to
deteriorate.
Further, when mounting a top shelf on four corner posts using the
SUPER ERECTA shelf system in utility cart applications, provision
should be made to resist disassembly of the top shelf from the
posts by upward movement that might result if an operator lifts the
top shelf, for example, to move the cart over an obstacle.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a modular
knock-down utility cart that has all of the advantages of prior art
of similar kind. That is the cart of the present invention is
intended to be easily manufactured, shipped, and stored as well as
easily assembled for use and disassembled thereafter.
It is a further object of the present invention to provide a
knock-down modular utility cart that utilizes improved structures
for mounting both intermediate shelves and a top shelf on four
supporting corner posts so that the shelves may be made
economically from plastic material such as structural foam.
It is a further object of the present invention to provide these
advantages in a utility cart which nevertheless exhibits structural
rigidity in all directions.
The knock-down modular utility cart in accordance with a preferred
embodiment of present invention comprises a plurality, preferably
four, of corner support posts that may be adapted from the
InterMetro Industries SUPER ERECTA shelf system. The cart further
includes at least one intermediate shelf and a top shelf. The
intermediate shelf is mountable on the posts and is formed with
four open collars, each one encircling one post. Each collar has a
cross-section substantially congruent to the cross-section of the
post and is formed with an upper tubular portion closely embracing
one post, a lower tubular portion having a downwardly, outwardly
inclined inner surface, and a transition portion between upper and
lower portions.
The top shelf is mountable in the region of the tops of the four
corner posts and is formed with a plurality of blind tubular
collars, each having a downwardly, outwardly inclined inner surface
and an inwardly projecting retaining flange at the bottom edge of
that surface. Each blind collar may also have an abutment surface,
similar to the transition portion of each open collar.
A plurality of sleeves, one for each open collar of each
intermediate shelf and one for each blind collar of the top shelf,
each includes an upper and lower edge and a right tubular inner
surface closely embracing a respective corner post. Each sleeve
also has a downwardly, outwardly inclined outer surface matable
with the lower portion of the inner surface of an open collar or
the inner surface of a blind collar.
Downward movement of the intermediate shelf, and thus the open
collars on the respective sleeves, causes the inclined inner
surface of each collar and inclined outer surface of each sleeve to
mate, thus compressing the sleeve inwardly toward the associated
corner post. Such downward movement is limited, however, by
abutment of the top edge of one sleeve with the transition portion
of the open collar.
Downward movement of the top shelf and thus the blind collars on
associated sleeves and posts causes each retaining flange initially
to override the outer surface of the associated sleeve and to
permit the outer surface of the sleeve to mate with the inner
surface of the blind collar. Additional downward movement causes
the blind collar to inwardly compress the sleeve toward the post
and causes the returning flange to underlie the bottom edge of the
associated sleeve. Subsequent upward movement of the blind collar
is resisted by engagement of the retaining flange with the bottom
edge of the associated sleeve.
The provision of the transition portion on the interior of each
open collar and its abutment against the top edge of the sleeve
eliminates the peripheral flange shown in U.S. Pat. No. 3,757,705
on which contaminants may collect. That is, the abutting surfaces
of the transition portion in the top of the sleeve are essentially
completely sealed from the outer environment but nevertheless
perform a downward movement limiting function important when the
shelves are made of a plastic material.
Further, the provision of the blind collar-sleeve structure
constitutes a simple and elegant system for restricting undesirable
upward movement of the top shelf and consequent unintended
disassembly of the utility cart. Thus, the top shelf, as well as
the intermediate shelf, may be made of plastic materials with
inexpensive molding techniques.
The foregoing and other objects and advantages of the present
invention may be more clearly understood from consideration of the
following detailed description of the preferred embodiments taken
in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a modular knock-down utility cart
constructed and assembled in accordance with a preferred embodiment
of the present invention.
FIG. 2 is a vertical cross-sectional view taken on plane 2--2 in
FIG. 1 and illustrating the improved structure for mounting an
intermediate shelf on a corner post.
FIG. 3 is a horizontal cross-sectional view taken on plane 3--3 in
FIG. 2.
FIG. 4 is a vertical cross-sectional view taken on plane 4--4 in
FIG. 1 and illustrating an improved structure for mounting the top
shelf on the corner posts.
FIG. 5 is a vertical cross-sectional view similar to FIG. 4 showing
another embodiment of an improved structure for securing the top
shelf to four corner posts.
FIG. 6 is a horizontal cross-sectinal view taken on plane 6--6 of
FIG. 5.
FIG. 7 is a vertical cross-sectional view similar to FIG. 4 and
illustrating another alternative embodiment of an improved
structure for securing the top shelf to four corner posts.
FIG. 8 is a perspective view of a metal boss used in the embodiment
of FIG. 7 to provide a retaining flange.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, the knock-down modular utility cart, generally
indicated at 10, in accordance with a preferred embodiment of the
present invention, includes four corner posts or columns 12, each
having a caster 14 mounted at its bottom end.
The cart further includes a top shelf generally indicated at 18 and
one or more (in the illustrated embodiment two) intermediate
shelves 20. The top shelf is secured at each of its four corners 22
to one of the posts 12 in the region of the top of the post.
Similarly, each intermediate shelf is secured in the region of each
of its corners 24 to one of the corner posts 12. The structures for
attaching the shelves to the respective corner posts, which will be
described in greater detail below, constitute a significant
improvement over the prior art.
The top shelf 18 may include a deck 26 for carrying articles (not
shown) and may be formed with a handle 28 at one end as shown in
FIG. 1, or at both ends if desired. Similarly, the intermediate
shelves 20 are each formed with a deck 30 also for carrying
articles (not shown).
Referring now to FIGS. 2 and 3, the structures for securing each
intermediate shelf 20 to the corner posts 12 will now be described
in detail. As shown there, each post is a right cylinder and is
formed with a plurality of annular grooves 16 at regular intervals,
for example, one inch, along its length.
Each intermediate shelf 20 is formed at each corner 24 with an open
collar 32, that is, open at both ends, extending vertically
therethrough. The collar includes an upper section 34 formed as a
right cylinder that closely embraces the outer surface of one post
12. The collar further includes a frustoconical lower section 36
having an inner surface downwardly and outwardly inclined at a
moderate angle with respect to the axis of the collar. A transition
section 38, also having frustoconical form, is inclined downwardly
and outwardly at an angle of approximately 45 degrees between the
upper and lower sections 34 and 36.
Interposed between the lower section 36 of the collar 32 and the
post 12 is a frustoconical sleeve 40 having a right cylindrical
inner surface 42 that closely embraces the outer surface of the
post 12. Further, the sleeve is formed as two axially split halves
as can be seen in FIG. 3 and on its inner surface 42 has an annular
rib 44 that may interfit with any one of the annular grooves 16
provided on the post.
The sleeve also has a frustoconical outer surface 46 inclined
downwardly and outwardly at the same angle as is the lower section
36 of the collar 32. In the respects thus far described, the post
12 and sleeve 40 are conventional as is shown in U.S. Pat. No.
3,757,705 (Maslow), the disclosure of which is incorporated herein
by reference. However, the sleeve differs from that shown in the
'705 Maslow patent in that it has an upper edge 48 of frustoconical
form inclined downwardly and outwardly at an angle of 45 degrees.
Moreover, the sleeve has a lower edge 50 that directly joins the
outer frustoconical surface 46 in a fashion such as is illustrated
in U.S. Pat. No. 3,424,111 (Maslow), the disclosure of which is
also incorporated herein by reference. That is, the sleeve does not
incorporate a lower outwardly directed flange that might otherwise
arrest downward movement of the collar thereon relative to the
sleeve, but which also would have a tendency to collect
contaminants.
It will be appreciated that each intermediate shelf 20 may be
loaded vertically to urge it downwardly such that the frustoconical
inner surface of the lower section 36 of the collar 32 mates
tightly with the frustoconical outer surface 46 of the sleeve 40.
This interaction urges the sleeve radially inwardly toward the post
to tightly engage the annular rib 44 in an annular groove 16 thus
preventing further downward movement of the sleeve.
However, each intermediate shelf 20 is desirably made of a plastic
material such as structural foam and therefore may be subject to
plastic deformation or creep. Over time, if heavily loaded,
therefore, the lower portion 36 of the collar 32 may radially
enlarge or expand permitting the shelf and collar to move further
downwardly relative to the sleeve 40. However, such downward
movement is ultimately arrested by abutment of the top edge 48 of
the sleeve with the transition section 38 of the collar.
Significant plastic deformation to outwardly expand the lower
section of the collar then also stops.
It will be appreciated that by eliminating a lower outwardly
directed flange at the bottom edge of the sleeve, a structure
ordinarily which would collect contaminants, undesirable in
sanitary applications, is eliminated. Instead, the abutting
surfaces between the sleeve and collar are essentially sealed from
the outer environment and therefore do not readily collect such
contaminants. Thus, the system for mounting the intermediate
shelves on the corner posts constitutes a substantial improvement
over the prior art both in its particular design for fabrication
from low cost plastic materials and by eliminating an otherwise
unsanitary construction.
Reference will now be made to FIG. 4 for a description of the
improved device for securing the top shelf 18 in the regions of the
tops of the corner posts 12. As shown there, the post 12 includes a
final annular groove 16A near its top 52. A sleeve 40 of form
identical to that described with reference to FIGS. 2 an 3, is
mounted in the region of the top 52 of the post 12 with its annular
rib 44 received in the uppermost groove 16A.
The top shelf is formed with a blind collar 54 having a
frustoconical inner surface 56. At its upper edge, the inner
surface 56 terminates in a short frustoconical abutment section 58
inclined downwardly and outwardly at an angle of about 45 degrees
and adjacent that short section is a dome 60 having cylindrical
sides and a flat roof.
The blind collar 54 is formed at its lower extreme with an annular
inwardly directed retaining flange 60 that, in the assembled
condition shown in FIG. 4, underlies the bottom edge 50 of the
sleeve 40.
Thus, it will be understood that, as was the case with mounting of
the intermediate shelf with the corner posts through the sleeves,
downward movement of the top shelf will be limited by abutment of
the short frustoconical section 58 with the upper edge 48 of the
sleeve. At such extreme of downward movement, any upwardly
projecting portion of the post 12 extending above the sleeve 40 may
be received in the dome 60. Furthermore, upward movement of the top
shelf 18 and thus the blind collar 54 relative to the sleeve 40 and
post 12 will be resisted by interengagement of the retaining flange
62 with the bottom edge 50 of the sleeve. Therefore, the utility
cart of the present invention may be manipulated easily even by
lifting the top shelf, using the handle 28, to move the cart from
place to place.
The top shelf is assembled on to the posts and sleeves by inserting
one post and sleeve into each blind collar 54. Downward movement of
the top shelf causes the retaining flange 62 to override the
frustoconical outer surface 56 of the sleeve 40 until it underlies
the lower edge 50. At this time, the frustoconical inner surface 56
of the blind collar and frustoconical outer surface 46 of the
sleeve will tightly mate together urging the sleeve radially
inwardly to firmly secure the rib in the uppermost groove 16A in a
fashion similar to that described with reference to interaction of
the open collar 32 of the intermediate shelf 20 and the sleeve
40.
As shown in FIG. 4, the annular retaining flange extends about the
full circumference of the lower extreme of the blind collar 54.
However, an alternative is illustrated in FIGS. 5 and 6 in which
the retaining flange is formed as three arcuate sections 62A one on
each of three depending fingers 64. These flange sections 62 A
underlie the lower edge 50 of the sleeve in the same fashion as
does the flange 62 described with reference to FIG. 4.
Still a further embodiment of the retaining flange arrangement is
shown in FIGS. 7 and 8. In this embodiment, a cylindrical metal
boss 66 is secured in tight encircling relation about the blind
collar 54 by means of inwardly bent tangs 68 that grip the collar.
The cylindrical boss is formed at its lower edge with an inwardly
directed annular flange sections 62B to underlie the lower edge 50
of the sleeve 40 in the same fashion described with reference to
FIGS. 4 through 6. As can be seen in FIG. 8, each radially inwardly
directed flange section 62B may be formed on a depending finger cut
from the side walls of the boss 66 by means of vertically extending
slots 72 to enhance flexing of them when the boss is mounted by
being urged downwardly over the sleeve. The cylindrical boss
further serves to restrain radial outward plastic deformation of
the blind collar 54 when the top shelf is vertically loaded due to
interaction of the mating frustoconical surfaces of the collar and
sleeve.
In each of the embodiments shown in FIGS. 4 through 8, while the
flange 62 resists disengagement of the top shelf 18 from the four
corner posts 12 and sleeves 40, the top shelf may nevertheless be
disassembled from the posts and sleeves if desired by exerting a
sharp, relatively large upward force thereon.
Therefore, the utility cart of the present invention provides
notable advantages over similar knock-down, modular utility carts
known in the art. The cart of the invention incorporates improved
structures for mounting both top and intermediate shelves on corner
posts that provide improved sanitation as well as improved
assembly. The cart may be easily manipulated without accidental
disassembly. However, the cart can nevertheless be disassembled
when desired.
Although specific embodiments of the present invention have been
described above in detail, it is to be understood that this is for
purposes of illustration. Modification may be made to the preferred
embodiments of the knock-down modular utility cart described above
without departing from the scope of the present invention.
* * * * *